ECCOSTOCK® LoK is a low dielectric loss, low dielectric constant, material made of lightweight thermosetting plastic for RF and microwave applications. It weighs only about half that of polystyrene and one quarter that of polytetrafluoroethylene. Its dimensional stability is better than that of other low loss plastics, it has a very low thermal expansion coefficient and will not flow under cold or hot temperatures. It is also completely unicellular and not affected by moisture.

ECCOSTOCK® LoK is specifically designed for use in coaxial, waveguide and antenna support applications. Due to the low dielectric constant, reflections in transmission lines are minimized. RF coils wound on ECCOSTOCK® LoK exhibit a higher Q than when wound on polystyrene or other plastic stock. Soldering iron temperatures will not soften ECCOSTOCK® LoK and will only slightly degrade in the immediate area of contact.